Think Outside the Box. Strabismus & Amblyopia. Prescribing. Amblyopia 5/9/2017. Goals of today s lecture: Kacie Monroe, OD, FCOVD. Peripheral Movement

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1 Think Outside the Box Strabismus & Kacie Monroe, OD, FCOVD Goals of today s lecture: Define success in treatment Determine the best path to get there Spoiler: it may not be what you think Provide specific hands-on examples of techniques Model of Vision Keys to Success Peripheral Movement Gross Motor Balance Primitive Reflexes Prescribing Foundation of beginning good therapy is having the best functional prescription Lots of different opinions and schools of thought on what to prescribe Consider: Anisometropia/Aniseikonia Astigmatism Near point prescription Prism Contact lenses vs. spectacle correction Lenses are important and powerful! Never underestimate your ability to help a patient with lenses Standard definition varies Griffin & Borsting Reduced VA not correctable by refractive means and not attributable to ophthalmoscopically apparent structural or pathological anomalies or proven afferent pathway disorders Best correctable acuity is worse than 20/30. Burian Strictly speaking, any difference in acuity between two eyes represents an amblyopia of the eye with the poorer vision From a practical, clinical standpoint a difference in vision of two lines on a visual acuity chart is frequently used as a criterion for amblyopia. 1

2 Ciuffreda Functional amblyopia is a unilateral (or infrequently bilateral) condition in which the best corrected visual acuity in poorer than 20/20 in the absence of any obvious structural or pathologic anomalies, but with one or more of the following conditions occurring before the age of six years: Signficant anisometropia Constant unilateral esotropia or exotropia Significant isoametropia Significant unilateral or bilateral astigmatism Image degradation Sherman is a binocular condition manifested monocularly. The reduction of visual acuity is merely the presenting symptom. is a dysfunction that restricts an individual s ability to gather, process, analyze, and respond to visual information. is a problem primarily of binocular competition. Sherman (cont d) Adaptations made by the patient via neural inhibition and suppression cause abnormalities in ocular motility, fixation, accommodation, spatial localization, speed of perception, etc. The purpose of therapy is to maximize the patient s performance in visually related tasks such as academics, sports, and driving. Treatment can be expeditiously accomplished, and a long-term cure sustained, if the emphasis is on developing hig degrees of binocular function. The conventional approach of occlusion and full optical correction is rarely needed. Function of the amblyopic eye is generally worse in multiple areas Accommodation Oculomotor abilities Visual perception/spatial awareness In fact, the non-amblyopic eye performs worse than normal eyes of peers on these same evaluations Types of Refractive Anisometropia Isoametropia (high prescription) Strabismic Must be constant Usually esotropia Image degradation/form deprivation Ex: congenital cataract Eccentric Fixation Key: this is a biocular problem affecting monocular function You must measure EF with one eye occluded Fixation with some point other than the fovea Occlude the good eye and the amblyopic eye will fixate with a non-foveal point Note: refractive amblyopes normally have centric fixation while strabismic amblyopes normally have eccentric fixation 2

3 Evaluating EF Visuoscopy MIT Haidinger s brush After image transfer Monocular corneal reflex (angle kappa) Note: Be careful when refracting someone with EF, if you complete refraction monocularly, you will provide prescription for the eccentric point Consider Humphriss refraction (fog other eye) Patching First, think of the goal of treatment Should be normal binocular function (in most cases) Does it make sense to patch with end goal in mind? Fitzgerald & Krumholtz showed that vision therapy significantly improved maintenance of acuity gains. (They did use patching with therapy). Patching Some patching can be helpful However, active vision therapy is the best treatment Find a doctor at covd.org Patching If you don t patch, what DO you do? Biocular/Binocular tasks! Our goal is to improve binocular function, why not address that from the beginning? If you choose to patch, consider a spot patch so patient maintains peripheral function of the occluded eye Binocular Amblyopic Activities Polarized activities Vectograms Red/Green activities Dissociated prism activities Strabismus Esotropia, exotropia, hypertropia Constant vs. intermittent Comitant vs. noncomitant Monocular vs. alternating Post-surgical vs. no history of surgery Double vision vs. suppression Recent onset vs. long-standing Anomalous correspondance vs. normal correspondance Presence of: amblyopia, nystagmus, DVD, head turn/tilt 3

4 Strabismus Infantile Esotropia (not congenital) Usually presents 2-6 months of age Latent nystagmus and DVD common Accommodative Esotropia Usually presents 2-3 years of age Can be intermittent Note: Constant exotropia in a child is rare suspect ocular disease until proven otherwise Strabismus Dr. Bob Sanet s lecture changed my approach to strabismus treatment options Road #2 treatment Strabismus Goal Setting Case Report J.W. First step is to determine what success is for the patient/parent Specific goals Straighter eyes Less clumsy Better depth perception Better baseball performance Equal vision/acuity Stereopsis If you don t involve the patient in goal setting, they may not define success the same way you do! Anomalous Correspondence We must define this to continue our discussion Occurs when two foveas do not form corresponding points This is a brain adaptation (cortical) not retinal/ocular in origin The anomalous point does not have to remain constant Testing for ARC Luster Color Fusion Testing Bagolini lenses Hering-Bielschowsky After Image Test Amblyoscope Note: can show ARC on some tests and NC on others 4

5 How is that different than Eccentric Fixation? Anomalous correspondence is a binocular/biocular phenomena/adaptation AC and EF can coexist You must first evaluate presence or absence of EF before evaluating AC Some methods (After Image Test) won t work if patient also has EF Quiz Time Combine After Image transfer with MIT Goals determine treatment plan While sensory adaptations such as AC can impact likelihood of achieving binocular fusion, it does not impact ability to achieve improved cosmesis Road #2 In contrast to Road #1 that breaks AC and can cause double vision (which may or may not be short lived) Goals include: Improve cosmetic appearance by enhancing AC Improve performance in daily life Treatment Activities for Road #2 Syntonics Vestibular/VOR Primitive Reflexes Bilateral Integration Peripheral Fusion Key: Avoid all central and monocular tasks Exception: eye stretches Binasal Occlusion Two reasons: Esotropia (especially cross-fixation) Symptom relief (TBI, CI, etc.) Works especially well for VMS (Visual Motion Sensitivity) symptoms This is an imbalance between central/peripheral systems For esotropia, they are often moving their anomalous point so drastic cosmetic changes can happen quickly 5

6 Binasal Occlusion How to Apply Binasal Occlusion Materials: translucent scotch tape, black electrical tape, stippled clear nail polish, Bangerter foils Typically placed nasal to the pupillary-limbal margin Typically tilted approximately 15 degrees to allow better near viewing with convergence (less occlusion in lower portion of glasses) Use Streff wedge to measure or watch for improvement as you slide it Can apply to back/front of lenses or both Questions? Sources Cook, D. Optometric Evaluation and Treatment of Strabismus and. COVD, Etting, Gary. The Successful Treatment of Adult Strabismus: The Road Less Traveled. COVD, Sanet, R. San Diego Seminar series